"The bottom line," states the siren guidelines for the Johnson County Emergency Management Agency, "when outdoor warning sirens are heard, go indoors and tune into local media to get more information."

That's the advice the organizers of the Old Capitol Criterium followed when the county's emergency sirens rang out Sunday afternoon while bike racers, spectators and volunteers were on the streets of downtown Iowa City. After the sirens sounded, officials stopped the race, consulted local media and then allowed the race to resume for an abbreviated finish that got everyone to safety in time.

Other residents throughout the county, however, found themselves left wondering exactly what kind of precautions they should be taking:

• Should they just make sure to get indoors — out of the wind and hail?

• Or should they start taking the entire family into the basement and start hiding underneath a mattress.

With the peak of the severe weather season being from mid-April to May, now is as good a time as any to remind people what they are supposed to do if they are outside when the sirens sound.

Longtime Iowa City residents remember well when the emergency sirens rang out on April 13, 2006. That's when the weather suddenly turned unbearably muggy, the evening became eerily still, the sky faded to green and a roar like a freight train barreled through the downtown and some surrounding neighborhoods.

That's also when many Iowa City residents learned firsthand that there is no such thing as an "all clear" siren and that everyone needs to take cover inside when the sirens go off.

In the past eight years, however, many local residents may have forgotten those key lessons — especially considering how, back then, the county's warning system sounded everywhere throughout the county whenever there was a threat anywhere in the county. That led to a "cry wolf" syndrome in which people — even those outdoors — would ignore the sirens because they assumed the danger was dozens of miles away.

That's why we were glad a few years ago when Johnson County finally updated that system in favor of a new zone system. Now Johnson County is separated into three zones and emergency dispatchers are able to sound sirens only in portions of the county that could be affected by a severe weather threat.

The zone system should give people more confidence that they need to take action whenever the siren sounds. After all, as with the issue of flooding, it's not a question of if another severe storm system will hit; it's a question of when. Johnson County, on average, can expect to experience about four storms each year that would meet the siren guidelines.

But people also need to recognize that, in addition to tornado warnings, sirens also are sounded for severe thunderstorms if there are likely to contain either:

• Winds of 70 mph or greater.

• Or golf-ball-sized hail.

The average lead time between when the siren sounds and the severe weather hits is about 21 minutes for a storm and only about 10 minutes for a tornado. So when you hear the siren, remember the bottom line: "Go indoors and tune into local media to get more information."